Electrical safety controlling system for mine-cages



0 G. LEE AND A. ZESS.

ELECTRICAL SAFETY CONTROLLING SYSTEM FOR MINE CAGES. APPLICATION FILED OCT. 6, 1919.

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APPLICATION FILED OCT. 6, 1919.

Patented Dec. 21, 1920.

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51W OJcar lee efindren Zem UNITED STATES OSCAR G. LEE AND ANDREW ZESS, OF WASHINGTON, PENNSYLVANIA.

ELECTRICAL SAFETY CONTROLLING- $1 STEM FOR MINE-CAGES.

Application filed October 8, 1919.

Z '0 all whom it may concern Be it known that we, OSCAR G. LEE and ANDREW Znss, citizens of the United States, residing at Washington, in the county of Washington and State of Penns lvania, have invented certain new and use ul Improvements in Electrical Safety Controlling Systems for Mine-Cages; and we do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to electrical mineea c controlling systems.

)ne object of the invention is to provide an improved cage controlling system that renders it impossible for the motorman to accidentally or inadvertently lower a cage from its respective landings or raise it from the bottom landing until the eager is ready for the cage to be moved or has closed the circuit which drives the motor that effects movement of the cages, thereby enabling the cagers to protect themselves against injury by the premature moving of the cages.

A further object of the invention is to provide a system of this character which permits the motorman to have a limited control of the upper cage for raising it independently of the lower cage or without moving the latter until the lower eager permits its movement.

Other objects and advantages may become apparent to persons who read the following details of description in connection with the accompanying drawings in which:

Figure 1 is a diagrammatic view illustrating the complete system including three landings or stopping stations of the cages, all of the switches except one being open.

Fig. 2 is a view similar to Fig. 1, except the switches being closed and the automatic shorting switch and its connections being omitted.

Referring to the drawings in detail in which similar reference characters correspond with similar parts throughout the several views, a brief description will first be given of a previously well known system of which the present invention is an improvement and an extension, as follows:

A main circuit includes a generator 1, main conducting wires 2, 3, 4 and 5, a motor 6, a reversing circuit closer 7 and a non-reversing circuit closer 8, these circult closers being provided with solenoid cores extend Specification of Letters Patent.

Patented Dec. 21, 1920.

Serial No. 328,949.

ing respectively into solenoid coils 9 and 10. The coils 9 and 10 are elements of controlling oonductors which also include a cutout switch 11 and a motorinans master switch 12. This controlling circuit comprises three conducting wires 18, 14 and 15, the latter being a return conductor, the conductors 13 and 14: being connected with or including switch contacts 16 and 17 From the foregoing description, it will be seen that the current may be reversed in the main conductors 2, 3, 4:, and 5, so as to reverse the direction of the Inotors rotation, by moving the switch 12 from the contacts 16 to the contacts 17 and thereby deenergizing the coil 10 and energizing the coil 9, it being assumed, however, that the three wires 13, 14: and 15 are electrically connected together below and beyond the coils 9 and 10. The operation of reversing is as follows:

When the coil 10 is denergized, its spring 18 pulls the circuit closer 8 into the open-circuit position, and at the same time, the energized coil 9 pulls the circuit closer 7 into the circuit-closing position, as shown in Fig. 2. This reverses the circuit in a manner which will be understood by persons familiar with the art, and the motor 6 reverses its direction of rotation so as to lower the cage 19 which was previously raised and raise the previously lowered cage 20. It will be understood by those familiar with the art that the cages 19 and 20 are'raised and lowered through the medium of a cable 21 which extends around pulleys 22 and around a drum 23 which is driven by the motor 6.

The broken line cc diagrammatically represents one side of an elevator shaft or mine-shaft, the line AC representing the other side of the mine-shaft and one side of the tipple, the line AB representing the other side of the tipple, the line A-A representing the landing or stopping station at the top of the tipple, the line aa; representing the dumping station above the tipple, the line B--B representing the ground landing or stopping station, and line C-C representing the bottom landing or a land ing below the ground landing.

The system thus far described is well known to the public, being an ordinary means of operating and controlling the cage, and a great disadvantage of this system is that the motorman has unlimited control of the motor at all times, and it often occurs through a mistake, inadvertence or carelessness that the cages are moved while the cagers are in a position to be injured by movement of the cages.

The main purpose of this invention, therefore, is to enable the cagers to limit the control of the motor by the motorman to such an extent that the motorman is powerless to effect such movement of the cages that will endanger a cage-r while in the performance of his duties. To accomplish this purpose, a safety circuit extension is installed at and within the mine-shaft, this extension comprising three wires 24-, and 26, the latter being a return wire. These wires or conductors are adapted to be connected to the wires 13, 1 1- and respectively through the medium of a multiple switch generally indicated by the numeral 27. The three switch bars of his switch 27 are pivotally mount ed at the binding posts of the wires 13, i l and 15 and are movable into contact with the binding posts of the wires 24-, 25 and 26 so as to close the circuit between the ordinary controlling conductors and the safety circuit extension conductors 24, 25 and 26. If it becomes desirable to disconnect the circuit OX- tension conductors from the ordinary controlling conductors, and permit the ordinary controlling conductors to control the motor, the switch 27 may be swung into contact with a shorting; conductor 28 am thereby (1722?- plete the circuit of the ordinary controlling system independently of the safety circuit.

The wires 2% and 25 terminate in switch contacts on opposite sides of a switch arm 29, and a pair of conducting: wires 30 and 31 also terminate in contacts at opposite sides of the switch 29. lhe lower ends of the wires 30 and 31 terminate in contacts at opposite sides of a switch arm 32, the pivot of the switch 32 being connected with a conductor or wire 33 which has its upper end connected to a contact 34 which is positioned between two contacts 35 and 36 which are electrically connected respectively to the conductors and 25. The contacts 34:, and 36 are eng sable by a switch arm which has its pivot connected to the return wire 26. It will be seen, therefore, that when the switches 12, 29, 32 and 3'? are in the closed position shown in Fig. 2, the motor will be rotated in a given direction, wh reas, it the switches 12, 29 and 32 are moved in the opposite direction so as to break the circuit between the wires 24 and 31 and close the circuit between the wires 25 and 30, the motor will be reversed, and the upper cage will move do vnward while the lower cage moves upward. However, it either of the switches 29 or 32 are in the open position or in the opposite closed position from that shown in 2 while the motornians switch is in the closed position shown in Fig. 2, the circuit is incomplete, and the motor does not opcrate. It will be seen, therefore, that each of the switches 12, 29 and 32 must be closed in mutual agreement in order that the motor may be reversed after moving the cages to their upper and lower landings resp ctively. Therefore, when the co ers begin to pertorm their respective duties relative to the cages, they may either open the switches or lea 7c them unreversed, so that in case the motorman should reverse his switch by inadvertence, accident or mistake, such reversal oi the motormans switch will not reverse the motor. Moreover, there must be an agreement of the position of the switches 32 and 29 with one another as well with the switch 12, in order that the motor may be reversed. in other words, the switch 29 limits the control of the switch 32, the switch 32 limits control of the switch 29, and each of these switches limits control of the motormans switch 12, so that all three of these switches must be in agreement in order that the motor may be reversed.

The purpose and operation or"- the switch 5 "7 are as follows:

The switch 3'? is normally in closed relation with the contact 34:, so that the conductor 33 constitutes an extension of the return wire 26, and by breaking the circuit in this return wire in moving the switch 37 from the contact 34, the switches 29 and 32 are rendered ineffective, and moreover, by moving; the switch 37 to one ot the contacts or 36, the conductor 2 or 25 is short-circuited through the medium of the contact 35 or 36 and the connection of this contact with the conductor 24! or 25. Therefore, a eager or other person at the stopping station BB. b manipulating the switch 3?, can limit the control of the motormans switch 12 independently and exclusively of the switches 29 and In other words, the switch 37 is capable of rendering the switches 29 and 32 ineffective while limiting the control of the switch 12 so as to prevent the motor from being reversed by the latter. This switch 37 is useful and important in enabling the persons at the ground landing to control the motor so as to stop the cages at the ground landing; for permitting miners to pass to and from the cages. It will be noted that the switch 3. is not likely to be operated during normal operations of loading and unloading the cages, and should be operated only when an appropriate signal is received from the miners at the lower landing to indicate that they are in the cage and ready to be raised to the ground landing. Moreover, when miners are entering the cage to be lowered into the shaft, this cage is at the ground landing while the other cage is at a distance above the lower landing, and therefore, there lo no danger of injuring); iersons either at the lower landing or at the tipple landing.

Some mines are so arranged that the upper cage is raised an additional distance (from A-A to a a) after the bottom cage has stopped at the lower landing, so that the upper cage may be dumped while load ing of the lower cage is begun. In order to enable the motorman to effect this additional raising of the upper cage, three branch conductors 38, 39 and 40 are connected respectively, with the wires 13, 14 and 15, and the return connection 40 is connected to the pivot of a switch 41. The conductors 88 and' 39 terminate in binding posts 42 and 43 arranged to be engaged by the switch arm 41 alternately. The switch arm 41 may be provided with a rack 44 which meshes with a worm 45, and this worm may be connected to the shaft of the motor 6 by means of a shaft 46 a worm wheel 47 and a worm 48 directly connected to the motor shaft. It will be seen, therefore, that when the motor rotates in one direction, the switch arm 41 moves toward the contact 42, and when the motor rotates in the opposite direction, the switch arm 41 moves toward the contact 43. This form of automatically operated shorting device is merely illustrative of one of many devices that could be employed for automatically shorting the circuit to temporarily afford the motorman a special limited control of the motor which enables the upper cage to be raised from the landing A-A to the dumping station aa while the lower cage remains at rest. However, assuming that the switch arm 41 is engaged with the contact 42 while the motormans switch 12 is engaged with the contact 17, the motorman cannot now reverse the motor by shifting the switch to the contact 16 unless the circuit is closed through the medium of the switches 29 and 82, because if these latter switches are open, the circuit can only be closed by the switch arm 41 when the latter connects with the contact 42 and the motormans switch connects with the contact 17, or when the switch 41 connects with the contact 43 and the switch 12 connects with the contact 16. Nhen desired to return the upper cage from the dumping station to the tipple, this may be done by opening the switch 12 and releasing a brake (not shown), thereby permitting the cage to return by gravity, and in thus returning, the shaft of the deiinergized motor rotates and the switch 41 is moved to the circuit-breaking position after this cage reaches the landing A. A.

In some instances the switch 37 and its connections may be dispensed with, for instance, where the shaft has a surface landing used only for the convenience of the miners and for introducing supplies into the mine-shaft, but has no overhead tipple for dumping coal, there being no intermediate landing. In such instance, the return Wire 26 will extend to the pivot of the switch 32, and the conductor 33 will. be eliminated.

Although the conductors 2 and 3 are illustrated as a two-wire circuit, they may be included as elements of a three-wire circuit in the usual way when desirable, and these main conductors may carry either an alternating current or a direct current, according to the desires or attending requirements.

Although the shorting device, reversing device and several switches have been described more or less in detail, it is not intended to limit this invention to these exact details of construction and arrangement, but appropriate changes may be made with in the scope of the inventive ideas as implied and claimed.

lVhat we claim as our invention is:

l. The combination with a mine-cage controlling system including a reversible electric motor and a motor-revers1ng means, of an electric circuit extension of said system including two current controlling devices at diiferent stopping stations of the cage, these controlling devices being correlated with the motor reversing device in a manner to control the latter, one of these controlling devices being dependent on the other for its effectiveness in closing circuit with said motor-reversing means, said other device being capable of closing circuit with said motor-reversing means independently of the dependent one of these motor controlling devices.

2. The structure defined by claim 1, and a short-circuiting device operable by said motor for renderin the said current controlling devices ineffective.

The combination with an ordinary minecage operating and controlling system including a reversible electric motor and a motor-reversing means controllable by the motorman, of an electric circuit-extension including current controlling means at a lower stopping station of the cage, a current controlling means at an upper stopping station of the cage, these lower and upper controlling means beingbperatable respectively by the lower and upper cages to limit one anothers control of the motor and to limit the control of the motor by said motor-reversing means, and an intermediate current controlling means at a cagestopping station between the said lower and upper stopping stations, said intermediate current-controlling means being dependent upon the said reversing means and inde pendent of said lower and upper controlling means in completely closing the motorcircuit.

4. In a mine-cage operating and controlling system including cages and a hoisting cable, the combination of a main elec tric circuit including a motor to drive the cable and circuit closers operable to reverse the motor, an electric controlling circuit including a motormans switch operatable to control said circuit-closers, a cagers switch 01 )e1'ateble to limit the control of the motormzms switch, and a short-circuiting device operctable by said motor for controlling theeffect of the-motormans switch and rendering the cagers switch ineffective.

In testimony whereof we have hereunto 10 set our hands.

OSCAR G. LEE. ANDREW ZESS. 

